JPH0140039B2 - - Google Patents

Abstract

Erythromycin antibiotics of the formula: <CHEM> and their pharmaceutically acceptable acid addition salts, wherein R is hydrogen, alkanoyl having two or three carbon atoms and ethyl succinyl: R1 and R2 when considered separately are, respectively, hydroxy and hydrogen; R1 and R2 when considered together are an oxo group; R3 and R4 when considered separately are each hydrogen; and R3 and R4 when considered together are @C = O; processes for their preparation, and pharmaceutical compositions containing them.

Description

[Detailed description of the invention]

The present invention relates to novel semisynthetic macrolide antibiotics, particularly 4''-epierythromycin A and its 11,12-carbonate ester and 9-dihydro-4''-epierythromycin A and its 11,12-carbonate. It concerns esters. Erythromycin is used in Streptomyces erythreus (Streptomyces erythreus) in an appropriate medium as shown in US Pat.
erythreus) is an antibiotic produced during cultivation of a strain of the bacteria. Erythromycin is represented by the following structural formula and has two forms, A and B. A number of derivatives of erythromycin have been produced in an effort to modify its biological or pharmacological properties. US Pat. No. 3,417,077 describes the reaction product of erythromycin and ethylene carbonate as a highly active antibacterial agent. US Pat. No. 3,884,903 discloses 4"-deoxy-4"-oxo-erythromycin A and B derivatives useful as antibiotics, and US Pat. No. 4,150,220 discloses 4"- The novel synthesis of oxo-erythromycin A and its use as an intermediate leading to antibacterial agents is described. 9-Dihydroerythromycin A is described by K. Gerzon et al.
J.Am.Chem.Soc., 78 , 6396 (1956) and MV
J.Am.Chem.Soc., 78 , 388 (1956) by Sigal et al.
has been reported. The semi-synthetic macrolide antibacterial agent of the present invention is a compound represented by the following formula and a pharmaceutically suitable acid addition salt thereof. (wherein R is hydrogen, alkanoyl having 2 to 3 carbon atoms, or ethylsuccinyl; R ₁ and R ₂
are separately hydroxy and hydrogen;
R ₁ and R ₂ are together an oxo group; R ₃
and R ₄ are each independently hydrogen; and R ₃ and R ₄ together are C=O. ) A preferred group of compounds are those in which R ₁ and R ₂ are oxo groups. Especially preferred among this group are
4″-epi erythromycin A, 2′-acetyl-
4″-epi-erythromycin A, 4″-epi-erythromycin A11,12-carbonate ester and 2′-acetyl-4″-epi-erythromycin
A11,12-carbonate ester. A second group of preferred compounds are those in which R ₁ is hydroxy, R ₂ is hydrogen and R ₃ and R ₄ taken together are C=O. Particularly preferred within this group are 9-dihydro-4''-epierythromycin A11,12-carbonate ester and 9-dihydro-2'-acetyl-4''-epierythromycin A11,12-carbonate ester. A third group of preferred compounds are those in which R ₁ is hydroxy, R ₂ is hydrogen and R ₃ and R ₄ are each hydrogen. Among these, particularly preferred are 9-dihydro-4''-epierythromycin A and 9
-dihydro-2'-acetyl-4''-epi-erythromycin A. As one skilled in the art will appreciate,
Erythromycin macrolides having a substituent on the 11,12-hydroxy group can easily exist in the hemi-ketal form, and this form is in equilibrium with the keto form as shown below. In the present invention, it is fully expected that both of the above types exist, but for convenience,
All such structural compounds that can exist in the above two forms are written and named in the keto form. 4″-epi erythromycin A (R=H; R ₁ +
R ₂ = O; and R ₃ , R ₄ = H) in the presence of a Raney-nickel or noble metal catalyst in a reaction inert solvent.
4″-deoxy-4″-oxo-erythromycin A
(see US Pat. No. 4,150,220) and is easily produced by hydrogenating it. By reaction-inert solvent is meant one that dissolves the appropriate reagents but does not react to any appreciable extent with either the starting reagents or the final product. Solvents or mixtures thereof that are suitable for this reaction include lower alkanols such as isopropanol and ethanol. The reaction is advantageously carried out at room temperature and takes about 4 to 6 hours to reach substantial completion. It is often convenient to allow the reaction to proceed overnight. The ratio of reactants to Raney-nickel or precious metal catalyst is not critical, and it is preferred to use equal weights of Raney-nickel or precious metal catalyst and macrolide. Regarding hydrogen reactants,
An initial pressure of 3.4 atmospheres (50 psi) effectively provides the desired reduction without producing substantial amounts of by-products. The product can be isolated by conventional means. One preferred method consists of filtering the spent catalyst, concentrating the liquid and precipitating the product with water. R=H, R ₁ +R ₂ =O and R ₃ +R ₄ =C=O
The compound of the present invention is the corresponding compound in a reaction inert solvent.
4"-epi-erythromycin is synthesized by reacting with ethylene carbonate. The reaction can be carried out in a lower alkyl ester of an alkanoic acid, such as ethyl acetate, and is typically heated at reflux temperature for about 3 to 6 hours. To ensure that the reaction is complete, it is advantageous to use a 3 to 5 times excess by weight of ethylene carbonate relative to the macrolide.The excess may be used at the start of the reaction. However, it may also be added in portions throughout the reaction period. At the completion of the reaction, water is added and the product is extracted into the reaction solvent. The solvent is subsequently removed,
The residual product is purified by conventional means. Another method for producing 4″-epi-erythromycin A11,12-carbonate ester is to produce lane-deoxy-4″-oxo-erythromycin A in exactly the same manner as described earlier for the reduction of 4″-deoxy-4″-oxo-erythromycin A. - reduction of the corresponding 4"-deoxy-4"-oxo-erythromycin A11,12-carbonate (see US Pat. No. 4,150,220) using a nickel or noble metal catalyst and hydrogen. 4"-epi Acylation of erythromycin A or 4″-epi-erythromycin A11,12-carbonate esters produces their 2′-acyl derivatives.Experimentally, equimolar amounts of alkanoic anhydrides and the appropriate The macrolide is contacted in a reaction inert solvent. Preferred solvents are water-immiscible neutral solvents such as methylene chloride, toluene, ethyl acetate and chloroform. The reaction is carried out at room temperature, but at C. or heated to reflux. When carried out at room temperature, the reaction is substantially complete in 5 to 7 hours. Upon completion of the reaction, water is added, followed by The product is isolated from the organic phase and purified. Acylation of the 2'-hydroxy group is also carried out using acyl halides such as chloride or bromide.
When using such acyl halides as acylating agents, it is advantageous to add at least an equivalent amount of an acid scavenger such as sodium bicarbonate. Additionally, when the acylating agent is an acid halide, the preferred solvent is acetone and upon completion of the reaction the reaction mixture is poured into a water-water immiscible solvent mixture to isolate the product from the organic phase. do. 9-dihydro-4″-epi erythromycin A
is prepared by reducing 4″-deoxy-4″-oxo-erythromycin A (see US Pat. No. 4,150,220) with Raney nickel. The reaction is carried out at room temperature in a reaction inert solvent at an initial pressure of about 95.2 atmospheres (about 1400 psi). Under these reaction conditions, the reduction is usually complete in 12 to 14 hours, but it is advantageous to run it overnight to ensure complete reaction. Preferred solvents are lower alkanols such as ethanol, methanol or isopropanol. The ratio of Raney-nickel to macrolide is about 5 to 1 by weight. Upon completion of the reaction, filter the catalyst and concentrate the liquid to obtain the desired product;
It is purified by conventional means. 9-dihydro-4″-epi-erythromycin
A11,12-carbonate is advantageously prepared by treating 9-dihydro-4''-epi-erythromycin A and ethylene carbonate in a reaction-inert solvent such as toluene or benzene.4''-
As in the preparation of the 11,12-carbonate ester of epierythromycin A, it is preferred to complete the reaction using a 3- to 5-fold excess of ethylene carbonate over the macrolide. The excess amount may be added at the start of the reaction or may be added in portions during the reaction period. The reaction is about 40-60
Although carried out at 0.degree. C., the preferred reaction temperature is about 55.degree. At such reaction temperatures the reaction is about 4 to
Virtually complete in 5 hours. The product is isolated by treatment of the reaction mixture with water, acidification with acid to dissolve the macrolide in the aqueous phase, and subsequent basification after removal of undesired by-products and excess ethylene carbonate. It will be done. 9-dihydro-4″-epi-erythromycin
Another method to synthesize A11,12-carbonate ester is to reduce 4″-epi-erythromycin A11,12-carbonate ester with hydride. Experimentally, a volume ratio of 10:
The macrolide and a 10-fold molar excess of sodium borohydride are reacted in a mixed solvent of water and a lower alkanol such as ethanol in step 1. The reaction is advantageously carried out at room temperature and requires a reaction time of 1 to 2 hours. Upon completion, the reaction mixture is added to a water-water-immiscible solvent mixture (eg water-methylene chloride) and the product is then isolated from the organic phase. 9-dihydro-4″-epi-erythromycin A and 9
-Dihydro-4″-epi erythromycin A11,
Acylation of the 2′-hydroxy group of the 12-carbonate ester is achieved by the same method as previously described for the acylation of 4″-epi-erythromycin A and 11,12 carbonate esters. All reagents used in the manufacturing process are known in the art, are commercially available, or are described herein. 4"-deoxy-4"-oxo-erythromycin A macro The manufacturing method for rides is patented in the US
It is reported in specification No. 4150220. Among the compounds of the present invention, 4″-epierythromycin A, 2′-
Acetyl-4″-epi-erythromycin A, 4″-epi-erythromycin A11,12-carbonate ester, 2′-acetyl-4″-epi-erythromycin A11,12-carbonate ester, 9-dihydro-4″-epi-erythromycin A11,12- Carbonate ester, 9-dihydro-2'-acetyl-4''-epi-erythromycin A, 9-dihydro-4''-epi-erythromycin A and 9-dihydro-2'-acetyl-4''-epi-erythromycin A are Preferred for their usefulness. In utilizing these compounds of the invention in salt form for their chemotherapeutic activity, it is of course preferred to use pharmaceutically suitable salts. Some specific salts are unsuitable or undesirable for use directly in certain pharmaceutical applications due to their water insolubility, high toxicity, or lack of crystallinity; Toxic salts are converted to the corresponding pharmaceutically suitable bases by decomposition of the salts.Alternatively, they can be converted to the desired pharmaceutically suitable acid addition salts. Examples of acids to give include hydrochloric acid, hydrobromic acid, hydroiodic acid, nitric acid,
These include sulfuric acid, sulfite, phosphoric acid, acetic acid, lactic acid, citric acid, tartaric acid, succinic acid, maleic acid, gluconic acid and aspartic acid. The novel erythromycins described herein are effective against various Gram-positive bacteria such as Staphylococcus aureus and Streptococcus pyogenes, and certain Gram-positive bacteria such as spherical and oval shaped bacteria (cocci). Shows activity against negative bacteria in vitro. These activities are readily demonstrated by in vitro testing against various microorganisms in brain heart infusion medium using the conventional 2-fold serial dilution method. Their in vitro activity makes them suitable for external use in the form of ointments and creams; for sterilization and disinfection purposes of hospital room equipment; and as industrial antibacterial agents in water treatment, slime control or the preservation of paints and wood. It is useful as a. For in vitro use, eg, topical preparations, it is often convenient to formulate a given product with a pharmaceutically acceptable carrier such as vegetable or mineral oil or an emollient cream. Similarly,
They may be dissolved in liquid carriers or solvents such as water, alcohols, glycols or mixtures thereof, or other pharmaceutically acceptable inert vehicles that do not have a deleterious effect on the active ingredient. It may also be dispersed. For such purposes, active ingredient concentrations of about 0.01 to about 10% by weight, based on the total composition, are generally acceptable. Furthermore, many of the compounds of the present invention can be administered to animals (including humans) by oral and/or parenteral routes to in vivo Gram-positive bacteria such as Pasteurella multocida and Neisseria.
It is active against certain Gram-negative bacteria such as Neisseria sicca. When it comes to susceptible microorganisms, their in vivo activity is even more limited, and their degree of activity can be determined by treating mice of substantially uniform body weight with the test microorganisms and then treating them orally with the test compound. or determined by conventional methods consisting of subcutaneous treatment. Actually Mus musculus, for example
Ten mice are inoculated intraperitoneally with an appropriately diluted culture solution containing approximately 1 to 10 times the amount of LD100 (minimum concentration of microorganisms required for 100% lethality). At the same time, we conducted a control test,
In this test, mice are inoculated with a lower concentration dilution to check for possible changes in the virulence of the test microorganism. Test compounds were administered 0.5 h after inoculation and at 4, 24 and 48
repeated after an hour. Surviving mice are kept for 4 days after the last treatment and the number of survivors is recorded. When these new compounds are used in vivo, they can be administered orally or parenterally, for example by subcutaneous or intramuscular injection, at a dose of about 25 mg/day.
It is administered in amounts of Kg (body weight) to about 200 mg/Kg. Appropriate dosage range is about 150mg/Kg to about 200mg/day
mg/Kg. Suitable vehicles for injections are aqueous, such as water, saline, dextrose isotonic solution and Ringer's solution, or fatty oils from plants (cottonseed oil, peanut oil, corn oil, sesame oil), dimethyl sulfoxide and formulations. Other drainage vehicles (glycerin, propylene glycol, sorbitol) that do not interfere with the therapeutic efficacy of the drug and are non-toxic in the volumes and proportions used are non-aqueous. Furthermore, compositions are advantageously made that are suitable for extemporaneous preparation of solutions prior to administration. Such compositions include liquid diluents (e.g. propylene glycol, diethyl carbonate, glycerin, sorbitol, etc.), buffers, hyaluronidase,
It may also contain local anesthetics and inorganic salts to impart desired pharmaceutical properties. These compounds can also be used as solid diluents in the form of capsules, tablets, lozenges, troches, dry formulations, suspensions, solutions, elixirs and parenteral solutions or suspensions.
It may be combined with a variety of pharmaceutically acceptable inert carriers including aqueous vehicles and non-toxic organic solvents. Generally, these compounds are utilized in various dosage forms at concentration levels ranging from about 0.5% to about 90% by weight of the total composition. The following examples are presented for illustrative purposes only and are not to be construed as limiting the invention.
And many variations of the invention are possible without departing from the spirit or scope of the invention. Example 1 4"-epi-erythromycin A11,12-carbonate ester 109 g of Raney nickel sludge and 4"-deoxy-4"-oxo-erythromycin A11,12-carbonate ester in 1 part of absolute ethanol (U.S. Pat. No. 4,150,220) Reference) 109 g of the mixture was shaken at room temperature overnight under a hydrogen atmosphere of 3.4 atm (50 psi).The solids were filtered through a Supercel and the liquid was concentrated in vacuo to 550-600 ml.The concentrated liquid was placed in a steam bath. The solution was stirred at room temperature for 1.5 hours and the crystallized product was filtered and oven dried at 50° C. overnight to yield 59.8 g. The product was an ethanol-water mixture. Purification by recrystallization from solvent yielded 49.1g. Melting point
141-143℃, NMR spectrum ( _CDCl3 ) is 3.69
It showed absorption at (2H, q), 3.29 (3H, s), 2.27 (6H, s) and 1.58 (3H, s) ppm. Example 2 Absolute ethanol containing 100 g of 4″-epi-erythromycin A 11,12-carbonate ester A 4″-epi-erythromycin A 4″-deoxy-4″-oxo-erythromycin A (see US Pat. No. 4,150,220) A suspension containing 100 g of Raney nickel sludge in Example 1 was shaken at room temperature overnight under a hydrogen atmosphere of 3.4 atmospheres (50 psi). The spent catalyst was filtered through a Supercell and the liquid was concentrated in vacuo to 300ml. Add 700ml of water to the concentrated liquid
was added and the resulting milky solution was warmed on a steam bath. A small amount of ethanol was added so that the product precipitated out of solution without becoming gummy. 2 at room temperature
After stirring for an hour, the product was filtered and dried to obtain 57.6 g. The liquid was concentrated in vacuo until it became cloudy and the mixture was stirred for 1 hour, filtered and dried to yield 21.4 g.
I got it. The resulting harvest was combined. Melting point 141-144
℃. NMR spectrum (CDCl ₃ ) is 3.3 (3H, s),
It showed absorption at 2.3 (6H, s) and 1.4 (3H, s) ppm. In a similar manner, 200 mg of 4″-deoxy-4″-oxo-erythromycin A and 10% in 30 ml of methanol were added.
600 mg of palladium-charcoal was shaken under a hydrogen atmosphere for 4 hours, and 118 mg of 4''-epi-erythromycin A was obtained by the same finishing operation.B 4''-epi-erythromycin A11,12-carbonate ester 4 in 100 ml of ethyl acetate A mixture consisting of 10 g of erythromycin A, 20 g of ethylene carbonate and 5 g of potassium carbonate was heated under reflux for 3.5 hours. An additional 10 g of ethylene carbonate was added and heating continued for 2 hours. The reaction mixture was cooled to room temperature and stirred. The ethyl acetate phase was separated, washed successively with water (2 x 100 ml) and saturated brine solution (1 x 100 ml), and dried over sodium sulfate.The solvent was removed to form a viscous liquid. The residue was recrystallized from isopropyl ether-diethyl ether mixed solvent to obtain 2.54 g, which was recrystallized from isopropanol and then ethanol-water mixed solvent to give 896
I got mg. The product corresponded in all respects to that prepared in Example 1. Example 3 2′-acetyl-4″ epierythromycin
A11,12-Carbonate Ester To a stirred solution containing 1.3 g of 4"-epi-erythromycin A11,12-carbonate ester in 20 ml of methylene chloride was added 0.167 ml of acetic anhydride. The resulting reaction mixture was stirred at room temperature for 6 hours. The mixture was poured into saturated sodium bicarbonate solution. The organic phase was washed with water and saturated brine solution and dried over sodium sulfate. The solvent was removed in vacuo to give 1.28 g of product as a white foam. Isopropyl ether 904 mg of pure product was obtained by recrystallization from
212-214℃. NMR spectrum ( _CDCl3 ) is 3.29
It showed absorption at (3H, s), 2.25 (6H, s), 2.03 (3H, s) and 1.59 (3H, s) ppm. Example 4 2′-Propionyl-4″-epi-erythromycin A11,12-carbonate ester A solution containing 1.3 g of 4″-epi-erythromycin A11,12-carbonate ester and 0.227 ml of propionic anhydride in 20 ml of methylene chloride was mixed with
Stir for hours. The reaction mixture was poured into saturated sodium bicarbonate solution and the organic phase was separated and washed with water and saturated brine solution. The organic phase was dried over sodium sulfate and concentrated in vacuo to give 1.3 g of white foam.
I got it. The product was recrystallized from an acetone-water mixed solvent to obtain 888 mg. Melting point 209-213℃.
NMR spectrum (CDCl ₃ ) is 3.32 (3H, s),
It showed absorption at 2.24 (6H, s) and 1.59 (3H, s) ppm. Example 5 2'-(2-ethoxycarbonylpropionyl)
-4″-epi erythromycin A11,12-carbonate ester 4″-epi erythromycin in 15 ml acetone
A mixture of 1.3 g of A11,12-carbonate ester, 0.344 ml of ethylsuccinyl chloride and 1 g of sodium bicarbonate was stirred at room temperature for 3 hours. The mixture was poured into a water-methylene chloride mixed solvent. The organic phase was separated and washed with water and saturated brine solution. The organic phase was dried over sodium sulfate and concentrated in vacuo to give 1.4 g of a white foam. The product was recrystallized from isopropyl ether to yield 915 mg. Melting point 179-182℃. NMR spectrum ( _CDCl3 )
are 3.3 (3H, s), 2.61 (4H, s), 2.22 (6H, s)
It showed absorption at 1.57 (3H, s) ppm. Example 6 2'-acetyl-4''-epi-erythromycin A To a solution containing 14 g of 4''-epi-erythromycin A in 100 ml of methylene chloride was added 1.75 ml of acetic anhydride and the reaction mixture was stirred at room temperature for 2 hours. The mixture was poured into water and the pH was adjusted to 9 using solid sodium bicarbonate. The organic phase was separated, washed with water and saturated brine solution, and dried over sodium sulfate. The solvent was removed in vacuo to obtain 13.6 g of crude product;
This was recrystallized from a hexane-ethyl acetate mixed solvent to obtain 11.5 g. NMR spectrum ( _CDCl3 )
showed absorption at 3.3 (3H, s), 2.3 (6H, s), 2.0 (3H, s) and 1.4 (3H, s) ppm. Example 7 2′-propionyl-4″-epi-erythromycin A 4″-epi-erythromycin in 15 ml of acetone
0.34 ml of propionic anhydride was added to a suspension of 1.5 g of A, and the reaction mixture was stirred at room temperature overnight. The mixture was poured into methylene chloride and dilute sodium bicarbonate solution. The organic phase was separated and washed with water and saturated brine solution. After drying the organic phase over sodium sulfate, the solvent was removed in vacuo to yield 1.52 g of product. Purification was performed by recrystallization from an acetone-water mixed solvent to obtain 657 mg. Melting point 192~
195℃. The NMR spectrum (CDCl ₃ ) is 3.3 (3H,
s), 2.3 (6H, s) and 1.4 (3H, s) ppm. Example 8 2′-(ethoxysuccinyl)-4″-epi-erythromycin A 4″-epi-erythromycin in 15 ml of acetone
0.32 ml of ethylsuccinyl chloride was added to a suspension of 1.5 g of A and 1.0 g of sodium bicarbonate, and the reaction mixture was stirred at room temperature for 4 hours. Add an additional 0.106 ml of ethylsuccinyl chloride and stir for 1 hour.
It lasted for hours. The mixture was poured into methylene chloride and dilute sodium bicarbonate solution, and the organic phase was separated, washed with water and saturated brine solution, and dried over sodium sulfate. The solvent was removed under vacuum to give 1.7 g of crude product.
This was recrystallized from isopropyl ether to obtain 639 mg. Melting point 123-127.5℃. NMR spectra (CDCl ₃ ) are 3.3 (3H, s), 2.6 (4H, s),
It showed absorption at 2.2 (6H, s) and 1.4 (3H, s) ppm. Example 9 9-dihydro-4″-epi-erythromycin
A11,12-Carbonate Ester A solution containing 500 mg of 4″-epi-erythromycin A11,12-carbonate ester (Example 1) in 10 ml of ethanol and 1 ml of water was added to sodium borohydride with stirring at room temperature under a nitrogen atmosphere.
Added 249mg. The reaction mixture was stirred for 1.5 hours and then poured into a stirring water-methylene chloride mixed solvent to adjust the pH to 2.5. After 10 minutes the pH was adjusted to 11 and the organic phase was separated, washed with water and saturated brine solution and dried over sodium sulfate. The solvent was removed in vacuo to give 415 mg of crude product as a white foam. Using the product as an eluent, chloroform-methanol-ammonium hydroxide (97:3:0.03:v:
Silica gel 60 (230
~400 mesh) Chromatographed on 36g and 7ml
It was purified by collecting two fractions. Eluent ratio 90:10:0.03 with fraction 55
, and collected fractions 72 to 100 and combined them.
Removal of the solvent gave 209 mg of pure product. NMR spectra (CDCl ₃ ) are 3.26 (3H, s), 2.30 (6H,
s) and 1.46 (3H, s) ppm. Example 10 9-dihydro-4″-epi-erythromycin
A11,12-carbonate ester A 9-dihydro-4''-epi-erythromycin A 50 g (68.3 mmol) of 4''-deoxy-4''-oxo-erythromycin A (see US Pat. No. 4,150,220) in 500 ml of ethanol and Rane - A slurry containing 250 g of nickel was shaken overnight at room temperature under a hydrogen atmosphere with an initial pressure of 95.2 atm (1400 psi).The mixture was filtered through a Supercell and the liquid was concentrated in vacuo to give a colorless solid, which was Purification by recrystallization from acetone-water mixed solvent gave 37 g. Melting point: 139-143°C. NMR spectrum (CDCl ₃ ) was 3.31 (3H, s) and 2.31 (6H,
s) It showed absorption at ppm. B 9-dihydro-4″-epi erythromycin
A11,12-carbonate ester 9-dihydro-4″-epierythromycin in 2 flasks equipped with a mechanical stirrer and a thermometer
60 g of A, 300 g of ethylene carbonate, 150 g of potassium carbonate and 600 ml of toluene were added, and the mixture was stirred in an oil bath at 55° C. for 4.5 hours. The cooled reaction mixture was poured into 600 ml of water and the organic phase was separated and added to 600 ml of fresh water. The pH was adjusted to 2.5 and the organic phase was separated and discarded. The aqueous phase was washed with 600 ml of toluene, combined with 600 ml of methylene chloride, and the mixture was washed with 600 ml of toluene.
Adjusted the pH to 9.5. Separate the organic phase and add water (2x
400 ml) and saturated brine solution (1 x 400 ml) and dried over sodium sulfate. The solvent was removed in vacuo to obtain 98 g of crude product, which was purified by recrystallization from an ethanol-water mixture to give 28.5
I got g. Melting point 131-135℃. The product corresponded in all respects to that obtained in Example 9. NMR spectrum (CDCl ₃ ) is 3.26 (3H, s), 2.30 (6H, s)
It showed absorption at 1.46 (3H, s) ppm. Example 11 9-dihydro-2'-acetyl-4''-epi erythromycin A11,12-carbonate ester 9-dihydro-4''-epi in 15 ml of methylene chloride
0.214 ml of acetic anhydride was added to a solution containing 1.5 g of erythromycin A11,12-carbonate ester, and the reaction mixture was stirred at room temperature for 6 hours. The mixture was poured into 25 ml of water and the pH was adjusted to 9.5. The organic phase was separated, washed with water and saturated brine solution, and dried over sodium sulfate. Remove the solvent in vacuo to remove the product.
I got 1.4g. NMR spectrum ( _CDCl3 ) is 3.29
(3H, s), 2.55 (6H, s), 2.0 (3H, s) and
Absorption was observed at 1.43 (3H, s) ppm. Example 12 9-dihydro-2′-propionyl-4″-epi
Erythromycin A11,12-carbonate ester 9-dihydro-4″-epierythromycin in 15 ml of methylene chloride in the same manner as in Example 11.
1.5 g of A11,12-carbonate ester and 0.306 ml of propionic anhydride were reacted for 5 hours to yield 1.41 g of the desired product. NMR spectrum ( _CDCl3 )
are 3.32 (3H, s), 2.27 (6H, s) and 1.46 (3H,
s) It showed absorption at ppm. Example 13 9-dihydro-2'-(ethoxysuccinyl)-
4″-epi-erythromycin A11,12-carbonate ester To a stirred solution containing 9-dihydro-4″-epi-erythromycin A11,12-carbonate in 15 ml of acetone, add 1 g of sodium bicarbonate and then 0.421 ml of ethylsuccinyl chloride. The mixture was stirred at room temperature for 6.5 hours. The mixture was poured into a water-methylene chloride mixed solvent and the pH was adjusted to 9.5. The organic phase was separated, washed with water and saturated brine solution, and dried over sodium sulfate. The solvent was removed under vacuum to yield 1.6 g of the desired product. Pharmacological Test Example 1 The compound of the present invention, 4″-epi-erythromycin A (produced in Example 2A) (hereinafter referred to as Compound 1) and the erythromycin A disclosed in column 127-44 of U.S. Pat. No. 4,150,220 (hereinafter referred to as Compound 1) (abbreviated as compound 2)
Staphylococcus aureus
01A005, Streptococcus pyogenes (Str
The in vivo activity against infection with Streptococcus pyogenes 02C203 and Streptococcus pneumoniae 02J012 was measured as follows, and PD ₅₀ was calculated. Methods Mice were subjected to acute systemic infection by intraperitoneal inoculation with standardized bacterial cultures suspended in 5% porcine gastric mucin. The inoculum dose was generally 1 to 10 times the lethal dose, ie, 1 to 10 times the number of bacteria required to kill 100% of the mice within 4 days. Dosing for all experimental infections began 30 minutes after bacterial inoculation, followed by oral administration 4 and 24 hours later. After 4 days, the 50% protective dose (PD ₅₀ ) (mg/
Kg) using the probit method (Baston, HE1957, An
Introduction to Statistics in Medicinal
Sciences, p64-67, Burgess Publishing Co.,
Calculated by (Minneapolis). PD ₅₀ refers to the dose of antibiotic (mg/Kg) at which treatment protects 50% of mice from fatal infection. The results are shown in the table below.

[Table] Ness
(Strept.pyogenes)02C203
Streptococcus pneumoniae 20.6 33.1
(Strept.pneumoniae)02J012
In the above comparison in vivo, which simulated an actual infectious disease state, the 4''-epi-erythromycin A of the present invention showed much superior activity against three types of bacteria than the conventional erythromycin A. Pharmacological test Example 2 The efficacy of 4''-epi-erythromycin A and erythromycin A was determined and compared in mice, rats and dogs, and the maximum serum concentrations of these two compounds were calculated. 4''-epi-erythromycin A or erythromycin A was administered orally diluted in a diluent consisting of water, carboxymethylcellulose, and Tween. Mouse and rat serum was collected using the intraorbital sinus bleeding technique [Salem et al., J. Pharm.Sci. , 52 , 794
(1963)]. Beagle dog serum was obtained from clotted blood samples obtained by jugular venipuncture. Bioassays were performed using Micrococcus lutea (ATCC 9341) as the test organism using a conventional large disk assay. Standard curves for mouse, rat and dog serum assays were generated with serum from normal animals. The peak serum concentrations (μg/ml) of 4″-epi-erythromycin A and erythromycin A were obtained by measuring the serum concentrations over time. The results are shown in the table.

[Table] As is clear from the above results, the serum concentration of 4″-epi-erythromycin A of the present invention was unexpectedly high in all animals compared with erythromycin A. Invention 4″-epi-erythromycin A
The acute toxicity ( _LD50 ) of Animal Administration Route LD ₅₀ (mg/Kg) Mouse Oral ＞5000 Rat Oral ＞2000 Mouse Intraperitoneal 530 Rat Intraperitoneal 1238 As is clear from the above, the acute toxicity of 4″-epi-erythromycin A hardly needs to be considered. The NMR spectrum (CDCl ₃ ) is 3.31 (3H, s),
2.62 (4H, s) 2.27 (6H, s) and 1.47 (3H,
s) It showed absorption at ppm.

Claims (1)

[Scope of Claims] A compound selected from the group consisting of primary macrolide antibiotics and a pharmaceutically suitable acid addition salt thereof. (wherein R is selected from the group consisting of hydrogen, alkanoyl having 2 to 3 carbon atoms and ethylsuccinyl; R ₁ and R ₂ are separately hydroxy and hydrogen, respectively; R ₁ and R ₂ together are is an oxo group; R ₃ and R ₄ are separately each hydrogen; and R ₃ and R ₄ together are C=
It is O. ) 2 The compound according to claim 1, wherein R ₁ and R ₂ together represent an oxo group. 3. The compound according to claim 2, wherein R is hydrogen and R ₃ and R ₄ are each hydrogen. 4. The compound according to claim 2, wherein R is acetyl and R ₃ and R ₄ are each hydrogen. 3. A compound according to claim 2, wherein 5 R is hydrogen and R ₃ and R ₄ together are C=O. 3. A compound according to claim 2, wherein 6R is acetyl and _R3 and _R4 taken together are C=O. 7 R ₁ is hydroxy, R ₂ is hydrogen and R ₃ and
2. A compound according to claim 1, wherein R ₄ taken together are C=O. 8. A compound according to claim 7, wherein R is hydrogen. 9. A compound according to claim 7, wherein R is acetyl. 10. A compound according to claim ₁ , wherein R 1 is hydroxy, R ₂ is hydrogen and R ₃ and R ₄ are each hydrogen. 11. A compound according to claim 10, wherein 11R is hydrogen. 12 Claim 10 in which R is acetyl
Compounds described in Section. 13. An antibacterial composition comprising a compound of formula (13) or a pharmaceutically suitable acid addition salt thereof and a pharmaceutically acceptable carrier. (wherein R is selected from the group consisting of hydrogen, alkanoyl having 2 to 3 carbon atoms and ethylsuccinyl; R ₁ and R ₂ are separately hydroxy and hydrogen, respectively; R ₁ and R ₂ together are is an oxo group; R ₃ and R ₄ are separately each hydrogen; and R ₃ and R ₄ together are C=
It is O. )